1. Field of the Invention
This invention relates to sewing machines in general, and more particularly to a work feeding mechanism which permits a fabric or garment to be fed past the stitch forming area in directions defined by two mutually orthogonal axes.
2. Description of the Prior Art
Sewing machines having mechanical elements for effecting fabric feeding to the right or left sides of a normal line of feeding are known in the prior art. Such machines frequently employ cams which impart fabric feeding motion to the feed dog through mechanical arrangements which are difficult to manipulate to achieve a variety of intricate stitch patterns. Sewing machines are also known in the prior art which employ linear actuators to permit the production of intricate ornamental stitches from patterns which are stored in electronic memories. See for example U.S. Pat. No. 3,855,956 which issued to Wurst on Dec. 24, 1974 which is owned by the assignee of this invention and the teachings of which are incorporated herein by reference. While such machines have the capability of producing a wide variety of ornamental stitches, they are not able to produce stitches in which the pattern width, or bight exceeds the maximum relative displacement between the sewing needle and the looptaker at which a stitch may be formed.
Sewing machines are also known in which a periodic swinging of the needle bar while the needle is penetrating the material being sewn produces lateral fabric feeding motion to the right or left of the normal line of fabric feeding. With such work feeding mechanisms however, the ability of the sewing machine to produce zig zag stitch patterns while feeding to the right or left is curtailed.
The prior art does not disclose a sewing machine work feeding mechanism which intermittently engages and transports the work in response to electronic signals stored in an electronic memory for transporting the fabric being sewn past the needle in any direction. The implementation of such a mechanism provides a sewing machine having the capability of stitching straight or zig zag patterns over large areas not necessarily confined to the width of permissable zig zag stitching.